Method and apparatus for rendering a corrugated carton readily openable



E. J. KANE Feb. 1, 1966 3,232,154

METHOD AND APPARATUS FOR RENDERING A CORRUGATED CARTON READILY OPENABLE 5 Sheets-Sheet 1 Filed May 10, 1963 INVENTOR. EUGENE J. KANE BY Emu/- 6, 14., QM avg his ATTORNEYS E. J. KANE 3,232,154 METHOD AND APPARATUS FOR RENDERING A CORRUGATED Feb. 1, 1966 CARTON READILY OPENABLE 5 Sheets-Sheet 2 Filed May 10, 1963 m GD INVENTOR. EUGENE J. KANE his ATTORNEYS 5 Sheets-Sheet 5 III II' INVENTOR. EUGENE J. KANE his ATTORNEYS BY imu g 1:

E. J. KANE CARTON READILY OPENABLE t H 1 i Q? a i Feb. 1, 1966 METHOD AND APPARATUS FOR RENDERING A CORRUGATED Filed May 10, 1963 Feb. 1, 1966 E. J. KANE 3,232,154

METHOD AND APPARATUS FOR RENDERING A CORRUGATED CARTON READILY OPENABLE Filed May 10, 1963 5 Sheets-Sheet 4.

TO PILOT VALVE 65 TO PILOT I 6 VALVE 47 I FIG. 5

INVENTOR. EUGENE J. KANE his ATTORNEYS Feb. 1, 1966 Filed May 10, 1963 E. METHOD AND APPARATUS FOR RENDERING A CORRUGATED J. KANE 3,232,154

CARTON READILY OPENABLE 5 Sheets-Sheet 5 $282535 ?8 DEVICE SOLENOID I05 10/ I00 I28 TIMER I24 POWER I26 I76 STOP M0 sCuRCE I BAR I 3 Bi/ I38 SOLENOID I34 I02 I46 CUTTING LIFT DEVICE CYLINDER CYLINDER PILOT VALVE PILOT VALVE I I 65 l J 99 QIEI I CYLINDER PILOT VALVE INVENTOR. EUGENE J. KANE BY JMYM z ZL LW ,e' M

his ATTORNEYS United States Patent Ofiice 3,232,154 Patented F eh. I, 1966 3,232,154 METHGD AND APRARATUS FOR RENDERI-NG A QGRRUGATED CARTUN READILY ()PENABLE Eugene Kane, Nutley, N.J., assiguor to Thomas I. Lipton, inc Hohoken, N..l., a corporation of Delaware Filed May 10, 1%3, Ser. No. 279,444 12 Claims. (Cl. 83-1) This invention relates to corrugated structures and, more particularly, to a method of rendering-readily separable a corrugated board member and one or more second members adhered together along flatwise abutting surfaces, to a corrugated board which is readily separable from an adjacent member to which it is adhered and to apparatus for rendering a corrugated carton readily openable.

There are many situations wherein a corrugated board member is adhered to a second member and must be separated therefrom. For example, a wide variety of products are packaged for transport, storage and sale in cartons fabricated from corrugated board consisting of outer webs or plies connected together by a corrugated .ply. While a number of forms of closures for such cartons are in use, the most common is a closure'formed from end flaps and side flaps, which are contiguous to the sides of the carton and are then folded inwardly so that the end flaps underlie the side flaps. The mutually contacting areas of the underlying and overlying flaps are glued together.

A significant disadvantage of this typeof carton is its inability to be quickly and easily opened. Generally, it is necessary to cut off the complete closure of the carton using a knife or a razor blade tool. While this method is, of course, effective to open the carton, it is laborious, slow and dangerous to the person opening it. More importantly, the knife or razor bladetool must cut completely through the wall of the carton to sever-the closure therefrom, and consequently often cuts or scratches the contents. The damaged merchandise must frequently be sold at a loss, and sometimes cannotbe sold at all.

A number of different methods for improving the closures of corrugated cartons to make them easier to open have been suggested such as, for example, several arrangements of tear away tapes and the use of special adhesives to join the flaps. None of the approaches so far suggested has been adopted on a Wide scale, either because of the difiiculty and expense of fabricating carton employing the ideas or because the methods are only partially effective to provide a readily openable carton.

There is provided, in accordance with the invention, a novel and improved method of rendering a corrugated board member readily separable from a second member which is adhered flatwise thereto. The method is to weaken or destroy the connection between the two outer plies of the corrugated board in selective portions of the glued-together areas of the members so that thetwo outer plies of the corrugated board can be readily separated from each other.

It is apparent that the methodinvolves disrupting the structure of the corrugated board member itself so that failure will occur between the two outer plies when the corrugated member is pulled away from the member adhered thereto. The force required to tear-the board apart can be reduced, in accordance with the degree to which the connection between the outer plies is disrupted, so that a minimum of human etfort is required to separate the outer plies.

There is alsoprovided, in accordance with the invention, a method of rendering the closure. of a corrugated carton more readiiy openable. The method involves weakening or destroying the connection between the outer plies in either the underlying or overlying closure flaps in selected portions of the glued-together areas of the flaps.

For example, the connection between the outer plies of the overlying flaps of a corrugated carton may be selectively destroyed in the areas which are glued to the underlying flaps of the carton. In the resulting carton, the overlying flaps are opened by inserting the fingers or an appropriate tool under them and pulling up. The two outer plies of the corrugated board in the glued areas are separated leaving the ply which is glued to the underlying .flaps still attached. After the overlying. plies are lifted,

: underlying flaps.

A further feature of the method, in accordance with the invention, is the formation of short cuts in the outer plyv of the weakened flaps which is adjacent and glued to the remaining. flaps. The cuts are made along lines defined by the ends .of the unweakened .flaps and extend a short distance from the ends vof the weakened flaps. Such cuts enable the .plies in which they are made to .sever .readilyalong a line defined by the ends .of the unweakened flaps. In otherwords, the small cuts .provide weakened points in vthe plies which will induce the remainder of the plies in the flaps to tear along predetermined lines.

Further, in accordance-with the invention, apparatus is provided for rendering a conventional, completely assembled and erected corrugated shipping carton readily openable. The apparatus includes a conveyor, means for guiding and holding one of the pairs of flaps of a carton in a predetermined position and means for selectively cuttingthe corrugated plies of those flaps, thereby weakening the connection between the outer plies of the corrugated board.

There is also. set forth herein, in accordance with the invention, a novel and improved closure for a corrugated plies ofthe corrugated board selectively disrupted sothat they are readily separated by hand upon pulling upon theoverlying flaps.

For a more completeunderstanding of the invention,

reference may be had,to the following detailed descrip- FIG. 2 is a partial perspective view of the closure of a carton which has been rendered readily openable, in accordance with the invention, after it has been opened partially;

FIG. 3 is a perspective view of an exemplary embodiment of apparatus for selectively slitting the overlying flaps of a completed, unclosed carton;

FIG. 4 is a side view in section of the apparatus shown in FIG. 3 and illustrates the sequence of operations performed on the cartons by the apparatus;

FIG. 5 is an end elevational view in section taken generally along the line 55 of FIG. 3, and in the direction of the arrows, showing the cutting blades and the lift mechanism in retracted positions;

FIG. 6 is an end view in section, on an enlarged scale,

of one side of the apparatus shown in FIG. 3, and illustrating the lift mechanism in its raised position and the blades inserted into the flaps; and

FIG. 7 is a schematic diagram of a control circuit for the apparatus shown in FIG. 3.

FIGS. 1 and 2 illustrate an exemplary method, in accordance with the invention, of rendering the closure of a carton readily openable. Shown therein is a conventional carton 18 having a closure formed by a pair of underlying flaps 12 and 12' and a pair of overlying flaps 14 and 14', all of which are hinged to the side walls of the carton and are folded over to lie in a single plane. In the example shown, all of the flaps are of equal height, the height being such that the ends of the overlying flaps 14 and 14' abut together when the carton is closed. The overlying flaps 14 and 14' are glued to the underlying flaps 12 and 12 in their mutually contacting areas to close the carton 10.

The carton 10 is fabricated from corrugated board consisting of an upper web or ply 16, a lower ply 18 and an undulating or corrugated ply 20. The corrugated ply 28 forms a multitude of interconnections between the upper and lower plies 16 and 18 by means of alternate generally straight portions and loop portions which are glued to the plies 16 and 18.

In accordance with the method of the invention the interconnections between the upper and lower plies 16 and 18 of either the underlying flaps 12 and 12' or the overlying flaps 14- and 14' are selectively disrupted in a the areas which are glued together when the carton is closed. The connection is destroyed to the extent that after the carton is glued closed, the overlying flaps can readily be torn away by hand using moderate force. The corrugated board itself fails structurally, either at the glue joints between the loops of the corrugated ply 2t) and the upper and lower plies 16 and 18, or in the corrugated ply by tearing of the uncut portions.

More particularly, FIGS. 1 and 2 show an embodiment of the method in which the overlying flaps 14 and 14' are weakened in the glued-together areas of the flaps by injecting a number of spaced-apart blades between the upper and lower plies 16 and 18 parallel to the corrugations to selectively cut the corrugated ply 20 approximately mid-way between the ends of the loops. The portion of the corrugated ply 20 which is cut may vary widely, depending upon the size of the box and the strength and gauge of the corrugated board. As shown in the drawings, the corrugated ply 20 is severed so that only approximately one-half of the connections afforded thereby between the upper and lower plies 16 and 18 remain intact.

After weakening the overlying flaps 14 and 14' the carton 10 is closed in the usual manner by folding down the underlying flaps 12 and 12 applying glue to their outer surfaces and then folding down the overlying flaps 14 and 14', thus forming glue joints 24 in the mutually contacting areas of the flaps.-

The carton is open by inserting the fingers or a suitable tool into the joint between the overlying flaps 14 and 14' at approximately the center, gripping the flaps and pulling them upwardly. As shown in FIG. 2, the areas of the overlying flaps 14 and 14' in which the connection between the upper and lower plies 1d and 18 has been selectively destroyed fail by separation of the plies. More particularly, the uncut portions of the corrugated ply 20 readily tear apart leaving loops attached to each of the upper and lower plies 16 and 18. The unglued center parts of the overlying flaps 14 and 14' are unaffected, the lower plies 18 in this portion tearing along lines defined generally by the ends of the glue joints between the underlying flaps 12 and 12' and overlying flaps 14 and 14', as shown in FIG. 2

It is preferable, in order to induce the tearing away of the lower plies 18, as described above, to make small cuts 25 at the ends of the overlying flaps 14 and 14' along lines define/.1 generally by the side edges of the underlying flaps 12 and 12. The cuts 25, which need not be more than about an inch in length, induce the failure of the lower plies 18 along the desired lines and also make them tearable by less force.

After the overlying flaps 14 and 14 are raised, the underlying flaps 12 and 12' are held down only by the lower plies 18 of the flaps 14 and 14' at their fold lines and the portions of the corrugated ply 28 which remain attached thereto. Accordingly, the underlying flaps 12 and 12' may readily be torn open with moderate force upon pulling up, thereby completely opening the carton.

It is clear, of course, that the method may be accomplished with equal success by weakening the underlying flaps 12 and 12 in the glued areas of the flaps. In this case, the overlying flaps 14 and 14 will tear away intact, carrying along the upper plies 16 of the underlying flaps 12 and 12. The lower plies 18 of the underlying flaps 12 and 12' are then easily torn away.

It is also apparent that the connection between the inner and outer plies 16 and 18 may be weakened, not only by cutting apart selected loops of the corrugated ply 20, but also by severing the glue joints between the loops and one or both of the plies 16 and 18 without substantially affecting the integrity of the corrugated ply 28.

It is important to note that the areas of the flaps which are weakened are those areas in which a double thickness of corrugated board is present. Consequently, there is no substantial degradation of the structural integrity of the completed carton. Therefore, the method may be employed without detriment to the strength of the shipping carton or limiting its handling and usage in the trade.

The method of rendering the closure of a carton more readily openable may be accomplished at any one of several stages in the processes of making the corrugated board or the fabrication of the carton. For example, the adhesion between the plies of corrugated board can be disrupted during its manufacture, thereby rendering the plies easily separable from each other. For example, one or both of the outer paper webs of the corrugated board can be pretreated to prevent the adhesion of selected ones of the loops of the corrugated ply to the outer plies. Such pretreatment may involve applying adhesive-resistant substances to the outer plies or the corrugated ply or the selective application of glue to the plies during the manufacturing of the corrugated board. Alternatively, a carton blank of conventional corrugated board may, during some stage of its forming, have its flap portions selectively weakened, or a completed carton may be rendered readily openable before being erected. Additionally, the method is not limited to rendering cartons more readily openable but is useful in any situation wherein a corrugated board or the like is to be removably adhered to another member.

An exemplary embodiment of apparatus, in accordance with the invention, suitable for carrying out the method described above on completed, unclosed cartons, before or after filling, is illustrated in FIGS. 3 to 7. The apparatus is automatically controlled to regulate the sequence of operations and is capable of handling the cartons very rapidly, thus making it well suited for production line use.

Referring to FIG. 3, the cartons are received on a continuous belt conveyor 26, driven in the direction of the arrow by a motor 27 through a belt drive 28, from, for example, a second conveyor 30 (shown in FIG. 4). Adjacent and above the side edges of the conveyor 26 and attached to a suitable frame are vertical side plates 32 and 32' arranged to guide and retain the cartons in position on the conveyor 26.

Mounted on a transverse support channel member 34 by a bracket 36 near the back of and above the conveyor 26 is a solenoid-operated pressing device 38 having a spring return 39 and arranged at a forwardly directed angle with respect to the conveyor. The solenoid of the pressing device 30 is energized, in a manner to be described in more detail hereinafter, and moves downwardly to fold over the rear underlying flap 12 into its closed position when a carton reaches a predetermined location.

As a carton is carried along the conveyor, a plow 40 folds down the front underlying flap 12' and engages the side or overlying flaps 14 and 14', holds them in an upstanding position and guides them into the space between the side plates 32 and 32 and a pair of holding plates 44 and 44'. The holding plates 44 and 44 are moved laterally in and out by a double-acting, spring-return air cylinder 46, which is mounted on transverse member 48. At a predetermined time, in response to a control system (described below), the plates 44 and 44 are actuated outwardly to hold the overlying flaps 14 and 14' firmly against the side plates 32 and 32'.

Below the conveyor belt 26, at the same station as the holding plates 44 and 44, is a lift mechanism comprising angle members 52 and 52 extending longitudinally with the belt 26 having upstanding legs spaced apart approximately the same distance as the side plates 32 and 32, a yoke 54 connected to the angles and an air cylinder 56. In response to the control system the lift mechanism 50 is moved upwardly and lifts the box vertically off the conveyor belt. The lifting takes place only after the carton has been stopped in a predetermined position by a solenoid-operated stop bar 58, which is mounted on side plate 32.

Mounted above the lift mechanism 50 and holding plates 44 and 44' is a cutting device 62. As best shown in FIGS. 4 and 5, the cutting device 62 is actuated by a spring-return air cylinder 64 mounted on a transverse frame member 66. Fastened to piston rod 68 of the cylinder 64 is a yoke 70 which carries a plurality of spaced-apart blades 72 installed in members 74 and 74. The blades 72 are slidably positioned in scabbards 76 and '7 attached to the side plates 32 and 32. Also mounted on the members 74 and 74 are slitting blades 78 having their cutting edges directed outwardly, as best shown in FIG. 1. At a predetermined time, in response to the control system, the blades 72 are plunged downwardiy, guided by the scabbards 76 and 76', between the upper and lower plies 16 and 18 of the overlying flaps 14 and 14'. The shorter outwardly directed blades 78 make the short cuts 25 in the lower plies 18 described previously.

Referring to the circuit diagram of FIG. 7, the motor 28 and a control system 99 are connected through a startstop switch 100 to terminals 101 and 102 of a power source 103, the motor 28 being connected thereto by leads 104 and 105, respectively.

The control circuit 99 includes a timer 108 which is connected by lead 110 to terminal 101 and by leads 112 and 114 to terminal 102 of the power source 103. The timer 108 controls the operation of the pressing device 38 and is started and stopped by a switch 115 mounted in the side plate 32, as best shown in FIG. 4, and connected in lead 110. A moving contact 116 of the timer 103 is connected to terminal 101 of the power supply 103 through leads 118 and 110. A fixed contact 120 is connected by lead 122 to one side of the solenoid of the pressing device 38. The other side of the solenoid is connected to terminal 102 of the power source 103 by leads 113 and 114.

A second timer 124 is connected by lead 125 to terminal 102 and by lead 126 through a switch 128 to terminal 101 of the power supply 103. The switch 128 is mounted on the angle 52 of the lift mechanism 50 somewhat rearward of the stop bar 58, as shown in FIGS. 4 and 5. A rotating contact 132 of timer 124 is connected by lead 134 to terminal 101 of the power source 103. The solenoid of stop bar 53 is connected between fixed contact 136 of the timer 124 and terminal 102 of the power supply 103 by lead 138 and by leads 140 and 114, respec tively.

Referring to FIG. 5, the air cylinders 46, 56 and 64 are connected to pilot valves 47, 57 and 65, respectively. The pilot valves may be of any known two-position type which is, for example, actuated by a solenoid. One of the positions of the pilot valves is connected to a source of pressure and the other to the atmosphere.

As shown in FIG. 7, the lift cylinder pilot valve 57 is connected to a fixed contact 142 of timer 124 by lead 144 and to terminal 102 of the power supply 103 by lead 114. Also connected to contact 142 is the holding-plate cylinder pilot valve 47, by lead 152 in which a switch 154 is intenposed. As shown in FIG. 5, the switch 154 is mounted on the outside of the side plate 32' and is closed by a spring arm 156 when the lift mechanism 50 is in its upper position. Pilot valve 65 of the cutting device 64 is connected to a fixed contact 146 of timer 124 by lead 148 and to power supply terminal 102 by lead 150.

Referring to FIGS. 4 and 7, the above-described apparatus operates in the following manner. When the start-stop switch 103 is closed, the motor 28 is started and drives the continuous belt conveyor 26 in the direction indicated by the arrows. A carton 10A moves along the conveyor and contacts control switch 115 starting the rotation of the moving contact 116 of timer 108. As the carton continues along on the conveyor, the rotating contact 116 moves around and contacts terminal 120, thereby energizing the solenoid of the pressing device 38 which turns down the rear underlying flap 12. The pressing device 38 then retracts when the rotating contact 116 of timer 108 moves off fixed contact 120.

Meanwhile, the previously deposited carton 10B has moved into contact with switch 128 closing a circuit to and starting timer 124. The rotating contact 132 of timer 124 reaches fixed contact 136 shortly before the leading side of carton 10B has moved up to the stop bar 53. Upon contacting the fixed contact 136, the timer energizes the solenoid of stop bar 58 pushing the bar out into the path of the carton and stopping its further movement along the conveyor. When carton 108 has stopped against the stop bar 5-3, the rotating contact 132 of timer 134 has moved onto fixed contact 142, thereby closing the circuit of the lift cylinder pilot valve 57 and opening the valve to a position that admits air pressure into the cylinder 56 from an air supply (not shown). The lift cylinder 56 raises yolk 54 and angle members 52 and lifts the carton 10B upwardly off the conveyor 26, as shown in FIG. 6. At this point, the moving contact 132 of timer 124 moves from fixed contact 136 and the solenoid of stop bar 58 is de-energized allowing it to retract.

Referring to FIGS. 6 and 7, when the lift mechanism 50 is in its raised position, the spring arm 156 contacts and closes switch 154, thereby making a circuit across the holding plate cylinder pilot valve 47, which opens to admit air pressure into cylinder 46. The cylinder 46 urges the holding plates 44 and 44 against the overlying flaps 14 and 14 of the carton 10B and holds them against the side plates 32 and 32'. When the rotating contact reaches fixed contact 146, a circuit is closed to the knife plunger cylinder pilot valve 65. The valve 65 is opened to the air pressure supply, and the blades 72 are plunged into the 7 overlying flaps 14 and 14. As shown in FIGS. 1 and 6, the blades 72 cut the corrugated ply 20, while the blades 73 make the previously described short cuts in the lower ply 18.

When the rotating contact 132 leaves the fixed contact 146 of timer 124', the circuit to the knife plunger cylinder pilot valve 65 is broken and the valve is opened to the air-vent position. A spring return in the cylinder 64 then withdraws the blades '72.v Shortly thereafter, the rotating contact 13.2 leaves fixed contact 142. Pilot valve 57 and pilot valve 47 are changed to their air vent positions, permitting the spring returns in cylinders 56 and 4d to withdraw the holding plates 44 and 44 and to lower the lift mechanism Eli, respectively. The carton B is redeposited onto the conveyor 26 and is carried away for completion of closing or for filling as the case may be.

When carton NB moves out of contact with switch 128, the timer i124 stops. Similarly, carton lllA leaves switch m5, stopping timer 3%. The apparatus and control system are now in readiness to repeat the operations described above.

It will be understood by those skilled in the art that the above-described embodiments are merely exemplary and are susceptible of variation and modification without departing from the spirit and scope of the invention. Therefore, the invention is not deemed to be limited except as defined in the appended claims.

I claim:

1. A method of rendering a carton readily openable, said carton having a closure including at least one corrugated flap having spaced-apart outer webs interconnected by a corrugated web having alternate generally straight portions and loop portions, said one flap adhered to at least one other flap in the mutually contacting areas thereof when the carton is closed, comprising the step, before the carton is closed, of destroying the interconnection between the outer webs of said one flap in selected portions of the mutually contacting areas so that said outer webs of said one flap are readily separable from each other.

2. A method of rendering a carton readily openable, said carton made of corrugated board consisting of a pair of spaced-apart outer webs interconnected by a corrugated web and having a closure consisting of a pair of underlying fiaps and a pair of overlying flaps, said flaps having mutually contacting areas adhered together when the carton is closed, comprising the step, before the carton is closed, of destroying the interconnection between the outer webs of the corrugated board of one of said pairs of fiaps in selected portions of the mutually contacting areas so that said webs of said flaps in said areas are readily separable from each other.

3. A method of rendering a carton readily openable, said carton made of corrugated board consisting of a pair of spaced-apart outer webs interconnected by a corrugated web and having a closure formed by a pair of underlying flaps and a pair of overlying flaps, said flaps having mutually contacting areas adhered together when the carton is closed, comprising the step, before the carton is closed, of destroying the interconnection in se lected portions of said overlying pairs of flaps in the mutually contacting areas of said flaps so that the outer webs thereof in said areas are readily separable from each other.

i. A method of rendering a carton readily openable, said carton made of corrugated board consisting of a pair of spaced-apart outer webs interconnected by a corrugated web and having a closure formed by a pair of underlying flaps and a pair of overlying flaps, said flaps having mutually contacting areas adhered together when the carton is closed, comprising the step, before the carton is closed, of cutting selected portions of the corrugated web of said overlying pair of flaps in the mutually con- 8 tacting areas of said flaps'so that the outer webs thereof in said areas are readily separable from each other.

5. The method as claimed in claim 4 further comprising the step of cutting the lower outer web of the overlying flaps generally along lines defined by the ends of the underlying flaps and beginning at the ends of the overlying flaps and extending a short distance therefrom.

d. A method of rendering a carton readily openable, said carton made of corrugated board consisting of a pair of spaced-apart outer webs interconnected by a corrugated web and having a closure formed by a pair of underlying flaps and a pair of overlying flaps, said liaps having mutually contacting areas adhered together when the carton is closed, comprising the step, before the car ton is closed, of cutting selected portions of the corrugated Web of said underlying pair of flaps in the mutually contacting areas of said flaps so that the outer webs thereof in said areas are readily separable from each other.

7. Apparatus for rendering a carton more readily openable, said carton made from corrugated board consisting ing of a pair of spaced-apart outer plies interconnected by a corrugated ply and having a closure consisting of a pair of underlying flaps and a pair of overlying flaps having mutually contacting areas adhered together when the carton is closed, comprising means for holding one of said pairs of flaps in a predetermined position, and means for cutting into said one pair of flaps to sever the interconnection between said outer plies in selected portions of the mutually contacting areas.

8. Apparatus for rendering a carton more readily openable, said carton made from corrugated board consisting of a pair of spaced-apart outer plies interconnected by a corrugated ply and having a pair of underlying flaps and a pair of overlying flaps having mutually contacting areas adhered together when the carton is closed, comprising conveying means, means for stopping the carton at a predetermined location on said conveying means, means for holding the overlying flaps in a predtermined position, means for cutting between the outer plies of the overlying flaps in selected portions of the mutually contacting areas to disrupt the interconnection therebetween, and means for cutting the lower outer ply of the overlying flaps generally along lines defined by the ends of the underlying flaps beginning at the ends of the overlying flaps and extending a short distance therefrom.

9. Apparatus for rendering a carton more readily openable, said carton made from corrugated board consisting of a pair of spaced-apart outer Webs interconnected by a corrugated web and having a pair of underlying flaps and a pair of overlying flaps having mutually contactng areas adhered together when the carton is closed, comprising conveying means, means at a first station along said conveying means for folding over the trailing underlying flap of the carton, means downstream of said first station for folding over the leading underlying flap and for guiding the overlying flaps into a predetermined position, means at a second station along said conveyor for stopping the carton, means for holding the overlying flaps in a predetermined position, and means for cutting between the outer webs of the overlying flaps in selected portions of the mutually contacting areas of the flaps to disrupt the interconnection between the outer webs.

10. Apparatus as claimed in claim 9, further comprising means responsive to the position of a first carton on the conveyor for controlling said folding means and means responsive to the position of a second carton on the conveyor for controlling said stopping means, holding means and cutting means.

11. Apparatus as claimed in claim 9, wherein said cutting means includes two sets of spaced-apart blades on each side of said conveying means, guide means for said blades, and means for actuating said blades downwardly at a predetermined time.

9 1O 12. Apparatus as claimed in claim 9, further comprising 2,751,964 1/1956 Guyer l56205 means for lifting a carton upwardly from said conveying 2,803,578 8/ 1957 Holland 156-250 means. 2,906,657 9/1959 Davidson 156250 3,065,540 11/1962 Magnatta 302 References Cit by the Examiner 5 3,137,068 6/1964 Quigley 30 2 UNITED STATES PATENTS 2,063,999 12/1936 Harrison WILLIAM W- DYER, Prlmary Ewmmer- 2 572 71 10/1951 George 156 205 FRANKLIN T. GARRETT, ANDREW R. JUHASZ,

2,747,788 5/1956 Tilly 22945 Examiners- 

1. A METHOD OF RENDERING A CARTON READILY OPENABLE, SAID CARTON HAVING A CLOSURE INCLUDING AT LEAST ONE CORRUGATED FLAP HAVING A SPACED-APART OUTER WEBS INTERCONNECTED BY A CORRUGATED WEB HAVING ALTERNATE GENERALY STRAIGHT PORTIONS AND LOOP PORTIONS, SAID ONE FLAP ADHERED TO AT LEAST ONE OTHER FLAP IN THE MUTUALLY CONTACTING AREAS THEREOF WHEN THE CARTON IS CLOSED, COMPRISING THE STEP, BEFORE THE CARTON IS CLOSED, OF DESTROYING THE INTERCONNECTION BETWEEN THE OUTER WEBS OF SAID ONE FLAP IN SELECTED PORTIONS OF THE MUTUALLY CONTACTING AREAS SO THAT SAID OUTER WEBS OF SAID FLAP ARE READILY SEPARABLE FROM EACH OTHER. 